Hermetic metal vessel



(No Model.)

C. E. CREECY,

HBRMBTIG METAL VBSSEL.

No. 457,849. v Patented Aug. 18, 1891.

1M: 'mam Pnens co., mimo-uwa, wuummcu. D. c.

` UNITED STATES PATENT OFFICE.

CHARLES EATON CREECY, OF l/VASHINGTON, DISTRICT OF COLUMBIA,

ASSIGNOR TO THE PNEUMATIC GUN CARRIAGE AND POVER COM- HERMETIC METAL VESSEL.

SPECIFICA'I'ION forming part of Letters Patent No. 457,849, dated August 18, 1891.

Application filel February 6, 1890. Serial No. 339,466. (No model.)

To all whom it may concern:

Be it known that I',CHARLEs EATON CREEOY, a citizen of theUnited States,residing at l/Vashington, in the District of Columbia, have invented certain new and useful Improvements in Hermetic Metal Ve'ssels; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it'appertains to make and use the same.

This invention relates to vessels for containing compressed air.

In pneumatio engines and in all apparatus in which compressed air is the motive agent the great difficulty encountered is leakage, this is owing to the porous nature of the metal of which the cylinders and reservoirs are constructed. To overcome this difficulty and provide absolutely air-tight chambers for the storage of the air under pressure is the object of this invention; and it consists in a cylinder of drawn cast-iron, steel, or other metal having its pores or interstices filled with heated sulphur in liquid form. By the application of great pressure, forcing the liquid sulphur into the pores and interstices of the metal, permeating the entire body or to sufficient depth, the same is rendered air-tight upon the evaporation of the liquid portion of the sulphur, which when cold expands and fills the pores or interstices of the metal.

In the accompanying drawing I have illustrated a simple and effioient means for treating the cylinders.

.A designates a cast-iron or other metal cylinder of ordinary construction; B, the cylinder-head loolted firmly thereto, the piston-rod Opening bin which is closed by a rod b', passing through and tightly held in a stuffingbox b.V

O designates a tube passing through the cylinder-head and communicating with the interior of the Chamber and providedtwith a cock c'.

The cylinder A is first charged with the sulphur D, which is reduced to a liquid state by heat. The advantage of employing sulphur as the impregnating substance is that when heated it will contract, so that after the metal into which it is forced is cooled said substance will expand, and thus entirely fill the pores or interstices. The liquefied sulphur is then subjected to great pressure-say fifteen hundred pounds, more or less--within the cylinder, which may be accomplished by means of pneumatio pressure through the tube O. This forces the liquid sulphur into the pores and interstices of the metal, permeating the entire body to considerable depth, according to the length of time the pressure is retained thereon. The cylinder is then relieved of the pressure, the surplus sulphur removed from the interior surface ,of the Chamber, the liquid which had been forced into the pores or interstices of the metal permitted to cool and harden therein or the liq- 'uid portion of the solution allowed to evaporate, leaving a sediment in the pores, thus effectually closing said pores or interstices, leaving the metal impervious.

The porosity of ordinary cast-iron or steel cylinders, such as now in common use in pneumatio apparatus, is very great, and when charged with air compressed at, say, four hundred pounds to the square inch, will leak so rapidly as to reduce the pressure to atmospheric in an hour or so. This is of course disadvantageous to the proper working of such apparatus and really renders it irregular and unreliable; Bya cylinder constrncted as herein described, however, I have been enabled to maintain a charge of air at over four hundred pounds pressure for an indefinite period with practically no lea-kage.

I am aware that heretofore wooden vessels have been impregnated with rosin, and also that it is not new to line or coat the inner surface of a fruit box or cask with sulphur; but I am not aware that prior to my invention metallic vessels have been rendered airtight by impregnating the pores or interstices thereof with heated liquor sulphur applied under pressure, so that when cooled the sulphur will expaud and thoroughly fill the pores or interstices.

While I have designated liquor sulphur as the impregnating agent employed, yet it will be understood that a composition of which liquor sulphur is the principal ingredient is within the scope of my invention.

IOO

Havng t'hus described my nventon, What In testimony whereof I aifix my signature in I claim 18-- presence of two witnesses.

As an improved article of manufacture a W f i f metallic eylinderfor pneumatic purposes hav- (*HARLES EAI'ON (JREEC' 5 ing its pores or nterstiees filled with sulphm', Wtnesses:

which is applied When heated in a liquid state C. S. MCNEIR,

and which expands When coo1ed,as set fol'th. H. J. MCLAUGHLIN. 

